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Simple Model For Active Isolation Of Machine Foundations By Open Trenches, S. Ahmad, T. M. Ai-Hussaini

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Ground disturbance due to waves generated by a machine foundation can be detrimental to adjacent structures or operation of sensitive equipment nearby. For machine foundations vibrating at moderate to high frequencies, the amplitude of ground motion can be reduced significantly by installing a wave barrier around the source. A three-dimensional boundary element algorithm incorporating quadratic elements has been used to perform an extensive parametric study on the effectiveness of open trenches as wave barriers. Based on the results of the study, a simple model in the form of an algebraic expression is developed for estimating the vibration screening effectiveness of …

Experimental And Numerical Investigation On Vibration Screening By In-Filled Trenches, S. Ahmad, J. Baker, J. Li

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

In-filled concrete and soil-bentonite trenches have been used in practice for many years as wave barriers to reduce transmission of moderate to high frequency ground vibrations generated by machine foundations or traffic. An experimental investigation on the influence of various geometrical and material parameters on vibration screening effectiveness of in-filled barriers has been conducted. The experimental data are compared with numerical (BEM) Solutions as well as with design formulas of Ahmad and Al-Hussaini (1991).

Screening Of Rayleigh Waves By Open Trenches, E. Conte, G. Dente

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

This paper presents results of a numerical study on the effectiveness of open trenches in reducing the ground vibration caused by propagating Rayleigh waves. The analysis is performed in the frequency domain and under conditions of plane strain using the Boundary Element Method. The soil is modelled as a homogeneous isotropic linear elastic half space. In order to represent the screening effect due to the installation of the barrier, the index ER is introduced. ER is defined as the ratio of the rate of energy transmission over the area to be protected in the presence of the trench and that …

Performance Of Port Facilities During The Northridge Earthquake, K. K. Muraleetharan, S. V. Jagannath, K. Arulmoli, D. A. Thiessen

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

During the January 17, 1994, Northridge earthquake, two of the Port of Los Angeles' facilities called Berths 121-126 and Pier 300 sustained moderate damage. Lateral displacement of dikes up to five inches and liquefaction of hydraulic fills were observed. Several geotechnical analyses from simplified SPT -based method to sophisticated fully-coupled analyses are presented. Observed lateral displacements are predicted reasonably well by the fully-coupled analysis procedure and an intermediate analysis procedure which incorporates some results from a fully-coupled analysis in to a simplified Newmark-type deformation analysis. The potential for higher pore pressure generation underneath the dike compared to a level ground …

Past Proceedings: Third International Conference On Recent Advances In Geotechnical Earthquake Engineering And Soil Dynamics, St. Louis (1995), Multiple Authors

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

Micromechanics Of Hot Mix Asphalt Material Formulation And Numerical Simulation, Kuo-Neng G. Chang

Dissertations

Hot Mix Asphalt (HMA), a highway and airfield pavement material, is heterogeneous, granular, and composite. It is traditionally modeled as a homogeneous material using continuum mechanics or semi-empirical methods. As a result, the above models either neglect or over-simply component reactions, failing to predict field performance problems resulting from particle segregation. This research presents micromechanical modeling, a novel approach that accounts for the components.

A micromechanical model is developed for HMA by modeling it as an assembly of asphalt cement coated particles. The asphalt cement is modeled as a viscoelastic material. To represent asphalt cement, several viscoelastic elements (i.e. Maxwell, …

Acuta Enews April 1995, Vol. 24, No. 4

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16th Conference On Senior Engineering Design Projects, College Of Engineering And Applied Sciences

Senior Engineering Design Conference

The 16th Conference on Senior Engineering Design Projects was held on April 11, 1995 at the College of Engineering and applied Sciences on the Parkview Campus of Western Michigan University. The college sponsors the conference to showcase the work of its graduating seniors, who are required to complete a capstone project that puts into practice what they have learned. Many of the projects are sponsored by business and industry.

Understanding Collaborative Writing Of Technical Proposals With A Process/Product Model, Frank Joseph Greco

Engineering Management & Systems Engineering Theses & Dissertations

Group work creates concerns with respect to performance, collaboration, and conflict management. Writing technical proposals creates appropriate settings for gaining insight into work group efficiencies and project conflict. The research involved different work groups preparing responses to Federal Government solicitations. A proposed Process/Product model was applied to create a new framework and perception of the technical proposal development effort. There exists a rich dialectic between the forces of Process, (how the effort is accomplished), and, Product, (what the effort will produce.) The investigation attempted to learn if the P/P model provides explanations for project conflict during technical collaborative writing.

The …

Optimizing Irrigation Management For Pollution Control And Sustainable Crop Yield, Ghassan R. Musharrafieh, Richard C. Peralta, Lynn M. Dudley, Ronald J. Hanks

Civil and Environmental Engineering Faculty Publications

Irrigation strategies which maximize crop yield while preventing salt from leaching to the groundwater or undesirable salt increases in the root zone are computed by using a one-dimensional simulation/optimization management model. The included constraint equations maintain a water volume balance and salt transport in the unsaturated zone. Implicit finite difference forms of the unsaturated water flow equation (Richards' equation), the diffusion-convection solute transport equation, functions describing the hydraulic properties of the medium, a root extraction function, and other constraints are used. The model uses a large discretization in time. A cyclic prediction and correction type of approach is adopted to …

Bs News

Building Services Engineering

No abstract provided.

Microwave Detection Optimization Of Disbond In Layered Dielectrics With Varying Thickness, Stoyan I. Ganchev, Nasser N. Qaddoumi, Emarit Ranu, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

The detection sensitivity optimization of air disbond in layered dielectric composites, using an open-ended rectangular waveguide, is studied both theoretically and experimentally. The sensitivity of the disbond detection is strongly influenced by the proper choice of parameters such as the operating frequency and the layered composite geometry (conductor backed or terminated by an infinite half-space of air). The capability of optimizing the measurement system parameters to detect and estimate the thickness of a disbonded layer independent of some changes in the thickness of the dielectric coating is also demonstrated. The impact of the parameters influencing detection optimization is theoretically investigated …

Acuta Enews March 1995, Vol. 24, No. 3

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Proceedings Of The First Annual Nebraska Aviation Education Association Conference, James E. Crehan, Uno Aviation Institute

Faculty Books and Monographs

UNOAI Report 94-5

Groundwater Model Parameter Estimation Using Response Surface Methodology, Richard M. Cotman

Theses and Dissertations

This thesis examined the use of response surface methodology (RSM) to estimate the parameters of a finite-element groundwater model. An existing two-dimensional, steady-state flow model of a fractured carbonate groundwater system in southwestern Ohio served as the calibration target data set. A Plackett-Burman screening design showed that only four of the ten hydraulic conductivity zones significantly contributed to the output of the finite-element model. Also, the effective porosity parameter did not significantly affect the model's output. Using only the four significant hydraulic conductivity parameters; four two-level, four-factor designed experiments were conducted to exploit the first-order response surface defined by a …

Excess Heat Capacity Surfaces For Water-Alkanol Mixtures By The Uniquac Model, Yaşar Demirel, Halime Ö. Paksoy

Papers in Physical Chemistry

Hydroorganic mixtures are industrial solvents that can serve as media to solubilize either water in hydrocarbon or a hydrophobic substance in water. In many cases the solubilizing capability is obtained via a homogeneous complex aqueous mixtures containing an alcohol. Since excess heat capacity C_P^E, is very sensitive to structural changes in mixtures, concentration and temperature dependence of C_P^E have been calculated by using the UNIQUAC model for the mixtures methanol(l)-water(%, ethanol(l)-water(2), and l-propanol(l)-water(2). The temperature-dependent parameters of the model estimated directly from C_P^E data at more than one different isotherm are used in …

Generalized Sylvester Theorems For Periodic Applications In Matrix Optics, Lee W. Casperson, Anthony A. Tovar

Electrical and Computer Engineering Faculty Publications and Presentations

Sylvester's theorem is often applied to problems involving light propagation through periodic optical systems represented by unimodular 2 × 2 transfer matrices. We extend this theorem to apply to broader classes of optics-related matrices. These matrices may be 2 × 2 or take on an important augmented 3 × 3 form. The results, which are summarized in tabular form, are useful for the analysis and the synthesis of a variety of optical systems, such as those that contain periodic distributed-feedback lasers, lossy birefringent filters, periodic pulse compressors, and misaligned lenses and mirrors. The results are also applicable to other types …

A Investigation Of Hydrogen-Storage Alloy As Catalytic Electrode For Hydrogenation Of Nitrobenzene, Shigang Lu, Hanxi Yang, Changfa Wan

Journal of Electrochemistry

Since hydrogen-storage alloy ean not only absorb hydrogen atoms to form highlyreactive metal hydride as hydrogen source by electrolysis but also possesses a certain catalytic activityfor hydrogenation,it is thus feasible to utilize the allov as a novel electrode for electrolvtichydrogenation in organic electroreduction. This work employed misch metal AB₅ type alloy as acatalytic electrode and studied the electrochemical hydrogenation of nitrobenzene.

The hydrogen-storage electrode (MH) was a plastic bonded electrode sheet made from a paste of Mm(NiCoMnAl)₅ alloy powder and teflon emulsion. The electrolysis was performed at constantcurrent and controlled potential in a three electrode cell of H-type …

Electrocatalytic Oxidation Of Formaidehyde And Formic Acid On A Pt/SbAd Electrode, Hong Li, Lincai Jiang, Xiong Jiang

Journal of Electrochemistry

The electrocatalytic activity for the oxidation of formaldehyde and formic acid ona Sb-modified platinum (Pt/Sb_ad) was investigated. Results showed that the Pt/Sb_ad electrode was electrocatalytically more active than a Pt electrode in the anodic oxidation of formaldehyde and formicacid. In the case of formaldehyde, an oxidation peak appeared at a potential of ca. 0.7V. During the oxidation of formic acid, a 4-fold increase in the 1st peak current was observed. The Sb-modified platinum electrode was found to be most electrocatalytically active at a coverage of 0.75±0.05. The electrocatalytic activity of the Pt/Sb_ad electrode can be best …

Acuta Enews February 1995, Vol. 24, No. 2

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Statistical And Finite Element Analysis Of The Effects Of Random Input Parameters On The Mechanical Characteristics Of Sheetmetal Forming Processes Using Quadrature Method, Yu Quan

Theses

In this thesis, the computer aided finite element analysis is implemented in the analysis of sheetmetal forming process. To rationalize the experimentation and analysis, the statistical method is introduced to study the variability of sheetmetal deformation process and final shape with respect to the variation of different parameters.

In Chapter 2, the basic characteristics and considerations of deep drawing operation is described with emphasis on the study of geometrical and physical variables of the forming process.

Chapter 3 discussed the three phases which are encountered in the computer aided finite element analysis. As a typical representative of professional finite element …

Single-Axis Agonistic Motion Control System With Electro-Magnetic Actuators, Alexander Rokhvarg

Theses

A novel single-axis motion control system using solenoid electromagnet actuators is built and successfully controlled using a non-linear real-time control algorithm. Procedures for defining and modeling the electromagnetic actuator are established and implemented. Discrete-time nonlinear control law with global asymptotic stability and zero steady-state error is designed and numerically optimized. Stable operation with small-signal 0dB crossover frequency of 370 Rad/sec and positioning RMS steady-state error of better than 4 micron is achieved. Time domain parameters are verified on a working prototype. A step reference response positioning a 0.35 Kg mass payload over 1 cm travel in under 30 milliseconds is …

Campus Telecommunications Systems: Managing Change, Association Of College And University Telecommunications Administrators

ACUTA: Other Publications

The purpose of this book is to provide a broadbased understanding of the rapidly changing environment of campus telecommunications. The anticipated audience for this material is the non-technical university administrator who may not have direct responsibility for telecommunications, but has a need to understand the general environment in which his telecommunications manager functions and the basic concepts of the technology. Five topic areas were selected that best cover the preponderance of issues. No attempt has been made to associate or closely coordinate materials from one chapter's subject to that of any other. Each chapter generally stands alone. In total, however, …

Multilevel Block Coded 8-Psk Modulations Using Unequal Error Protection Codes For The Rayleigh Fading Channel, Robert H. Morelos-Zaragoza, Tadeo Kamasi, Shu Lin

Faculty Publications

This paper introduces new block coded 8-PSK modulations with unequal error protection (UEP) capabilities for Rayleigh fading channels. The design of efficient block coded modulations (BCM) over 8-PSK signal sets, for the specific purpose of UEP, over Rayleigh fading channels is considered. UEP is desirable in communications systems where part of the source information is more important, or error sensitive, such as the transmission of coded speech and data broadcasting. The proposed block modulation codes are based on the multilevel construction of Imai and Hirakawa (1977). It is shown that the use of binary linear UEP (LUEP) codes as component …

In Vitro Characterization Of Transforming Growth Factor-Ss1-Loaded Composites Of Biodegradable Polymer And Mesenchymal Cells, S. B. Nicoll, A. E. Denker, R. S. Tuan

Cells and Materials

A porous, biodegradable polymer composite was fabricated from poly(L-lactic acid) (PLLA) using a solvent- casting particulate-leaching technique, and loaded with recombinant human transforming growth factor ß-1 (TGF-ß1). Tissue culture polystyrene (TCPS) and PLLA disks loaded with bovine serum albumin (BSA) served as controls. Polymer specimens were seeded at high cell density with C3H10T1/2 cells, a mouse embryonic cell line capable of differentiating into various connective tissue cell types. The polymer matrices degraded slowly in physiological saline over four weeks, with a sustained yet sporadic release of active TGF-ß1; a more controlled release of TGF-ß1 was observed in serum-containing culture medium …

Spring 1995, 90.9 Wmpg Fm

WMPG Program Guides

No abstract provided.

Fall 1995, 90.9 Wmpg Fm

WMPG Program Guides

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Summer 1995, 90.9 Wmpg Fm

WMPG Program Guides

No abstract provided.

Software And Hardware Requirements For Some Applications Of Parallel Computing To Industrial Problems, Geoffrey C. Fox

Northeast Parallel Architecture Center

We discuss the hardware and software requirements that appear relevant for a set of industrial applications of parallel computing, these are divided into 33 separate categories, and come from a recent survey of industry in New York State. The software discussions includes data parallel languages, message passing, databases, and high-level integration systems. The analysis is based on a general classification of problem architectures originally developed for academic applications of parallel computing. Suitable hardware architectures are suggested for each application. The general discussion is crystalized with three case studies: computational chemistry, computational fluid dynamics, including manufacturing, and Monte Carlo Methods.

Cell Adhesion To Crystal Surfaces: A Model For Initial Stages In The Attachment Of Cells To Solid Substrates, D. Hanein, B. Geiger, L. Addadi

Cells and Materials

This study addresses the mechanism of the chirally-restricted, ROD-independent adhesion of A6 epithelial cells to the {011} faces of calcium {R,R)-tartrate tetrahydrate crystals. The extensive and rapid adhesion of the cells to these surfaces, in the presence or absence of serum proteins, is distinctly different from the extracellular matrix-mediated adhesion to conventional tissue culture surfaces or to the {101} faces of the same crystals. The differences are manifested by insensitivity to ATP depletion, to disruption of microfilaments and microtubules and even to formaldehyde fixation of the cells. Furthermore, trypsin pretreatment does not affect cell attachment to the {011} faces, nor …